WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_ops.c


/*
 * Copyright (c) 2008 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup fs
 * @{
 */
 
/**
 * @file    fat_ops.c
 * @brief   Implementation of VFS operations for the FAT file system server.
 */
 
#include "fat.h"
#include "../../vfs/vfs.h"
#include <libfs.h>
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <string.h>
#include <byteorder.h>
#include <libadt/hash_table.h>
#include <libadt/list.h>
#include <assert.h>
 
#define BS_BLOCK        0
 
#define FIN_KEY_DEV_HANDLE  0
#define FIN_KEY_INDEX       1
 
/** Hash table of FAT in-core nodes. */
hash_table_t fin_hash;
 
/** List of free FAT in-core nodes. */
link_t ffn_head;
 
#define FAT_NAME_LEN        8
#define FAT_EXT_LEN     3
 
#define FAT_PAD         ' ' 
 
#define FAT_DENTRY_UNUSED   0x00
#define FAT_DENTRY_E5_ESC   0x05
#define FAT_DENTRY_DOT      0x2e
#define FAT_DENTRY_ERASED   0xe5
 
static void dentry_name_canonify(fat_dentry_t *d, char *buf)
{
    int i;
 
    for (i = 0; i < FAT_NAME_LEN; i++) {
        if (d->name[i] == FAT_PAD) {
            buf++;
            break;
        }
        if (d->name[i] == FAT_DENTRY_E5_ESC)
            *buf++ = 0xe5;
        else
            *buf++ = d->name[i];
    }
    if (d->ext[0] != FAT_PAD)
        *buf++ = '.';
    for (i = 0; i < FAT_EXT_LEN; i++) {
        if (d->ext[i] == FAT_PAD) {
            *buf = '\0';
            return;
        }
        if (d->ext[i] == FAT_DENTRY_E5_ESC)
            *buf++ = 0xe5;
        else
            *buf++ = d->ext[i];
    }
}
 
/* TODO and also move somewhere else */
typedef struct {
    void *data;
} block_t;
 
static block_t *block_get(dev_handle_t dev_handle, off_t offset)
{
    return NULL;    /* TODO */
}
 
static block_t *fat_block_get(dev_handle_t dev_handle, fs_index_t index,
    off_t offset) {
    return NULL;    /* TODO */
}
 
static void block_put(block_t *block)
{
    /* TODO */
}
 
static void fat_node_initialize(fat_node_t *node)
{
    node->type = 0;
    node->index = 0;
    node->pindex = 0;
    node->dev_handle = 0;
    link_initialize(&node->fin_link);
    link_initialize(&node->ffn_link);
    node->size = 0;
    node->lnkcnt = 0;
    node->refcnt = 0;
    node->dirty = false;
}
 
static uint16_t fat_bps_get(dev_handle_t dev_handle)
{
    block_t *bb;
    uint16_t bps;
   
    bb = block_get(dev_handle, BS_BLOCK);
    assert(bb != NULL);
    bps = uint16_t_le2host(((fat_bs_t *)bb->data)->bps);
    block_put(bb);
 
    return bps;
}
 
typedef enum {
    FAT_DENTRY_SKIP,
    FAT_DENTRY_LAST,
    FAT_DENTRY_VALID
} fat_dentry_clsf_t;
 
static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
{
    if (d->attr & FAT_ATTR_VOLLABEL) {
        /* volume label entry */
        return FAT_DENTRY_SKIP;
    }
    if (d->name[0] == FAT_DENTRY_ERASED) {
        /* not-currently-used entry */
        return FAT_DENTRY_SKIP;
    }
    if (d->name[0] == FAT_DENTRY_UNUSED) {
        /* never used entry */
        return FAT_DENTRY_LAST;
    }
    if (d->name[0] == FAT_DENTRY_DOT) {
        /*
         * Most likely '.' or '..'.
         * It cannot occur in a regular file name.
         */
        return FAT_DENTRY_SKIP;
    }
    return FAT_DENTRY_VALID;
}
 
static void fat_sync_node(fat_node_t *node)
{
    /* TODO */
}
 
/** Instantiate a FAT in-core node.
 *
 * FAT stores the info necessary for instantiation of a node in the parent of
 * that node.  This design necessitated the addition of the parent node index
 * parameter to this otherwise generic libfs API.
 */
static void *
fat_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)
{
    link_t *lnk;
    fat_node_t *node = NULL;
    block_t *b;
    unsigned bps;
    unsigned dps;
    fat_dentry_t *d;
    unsigned i, j;
 
    unsigned long key[] = {
        [FIN_KEY_DEV_HANDLE] = dev_handle,
        [FIN_KEY_INDEX] = index
    };
 
    lnk = hash_table_find(&fin_hash, key);
    if (lnk) {
        /*
         * The in-core node was found in the hash table.
         */
        node = hash_table_get_instance(lnk, fat_node_t, fin_link);
        if (!node->refcnt++)
            list_remove(&node->ffn_link);
        return (void *) node;  
    }
 
    bps = fat_bps_get(dev_handle);
    dps = bps / sizeof(fat_dentry_t);
   
    if (!list_empty(&ffn_head)) {
        /*
         * We are going to reuse a node from the free list.
         */
        lnk = ffn_head.next;
        list_remove(lnk);
        node = list_get_instance(lnk, fat_node_t, ffn_link);
        assert(!node->refcnt);
        if (node->dirty)
            fat_sync_node(node);
        key[FIN_KEY_DEV_HANDLE] = node->dev_handle;
        key[FIN_KEY_INDEX] = node->index;
        hash_table_remove(&fin_hash, key, sizeof(key)/sizeof(*key));
    } else {
        /*
         * We need to allocate a new node.
         */
        node = malloc(sizeof(fat_node_t));
        if (!node)
            return NULL;
    }
    fat_node_initialize(node);
    node->refcnt++;
    node->lnkcnt++;
    node->dev_handle = dev_handle;
    node->index = index;
    node->pindex = pindex;
 
    /*
     * Because of the design of the FAT file system, we have no clue about
     * how big (i.e. how many directory entries it contains) is the parent
     * of the node we are trying to instantiate.  However, we know that it
     * must contain a directory entry for our node of interest.  We simply
     * scan the parent until we find it.
     */
    for (i = 0; ; i++) {
        b = fat_block_get(node->dev_handle, node->pindex, i);
        for (j = 0; j < dps; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            if (d->firstc == node->index)
                goto found;
        }
        block_put(b);
    }
   
found:
    if (!(d->attr & (FAT_ATTR_SUBDIR | FAT_ATTR_VOLLABEL)))
        node->type = FAT_FILE;
    if ((d->attr & FAT_ATTR_SUBDIR) || !index)
        node->type = FAT_DIRECTORY;
    assert((node->type == FAT_FILE) || (node->type == FAT_DIRECTORY));
   
    node->size = uint32_t_le2host(d->size);
    block_put(b);
   
    key[FIN_KEY_DEV_HANDLE] = node->dev_handle;
    key[FIN_KEY_INDEX] = node->index;
    hash_table_insert(&fin_hash, key, &node->fin_link);
 
    return node;
}
 
static void fat_node_put(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
 
    if (nodep->refcnt-- == 1)
        list_append(&nodep->ffn_link, &ffn_head);
}
 
static void *fat_match(void *prnt, const char *component)
{
    fat_node_t *parentp = (fat_node_t *)prnt;
    char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
    unsigned i, j;
    unsigned bps;       /* bytes per sector */
    unsigned dps;       /* dentries per sector */
    unsigned blocks;
    fat_dentry_t *d;
    block_t *b;
 
    bps = fat_bps_get(parentp->dev_handle);
    dps = bps / sizeof(fat_dentry_t);
    blocks = parentp->size / bps + (parentp->size % bps != 0);
    for (i = 0; i < blocks; i++) {
        unsigned dentries;
       
        b = fat_block_get(parentp->dev_handle, parentp->index, i);
        dentries = (i == blocks - 1) ?
            parentp->size % sizeof(fat_dentry_t) :
            dps;
        for (j = 0; j < dentries; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                return NULL;
            default:
            case FAT_DENTRY_VALID:
                dentry_name_canonify(d, name);
                break;
            }
            if (strcmp(name, component) == 0) {
                /* hit */
                void *node = fat_node_get(parentp->dev_handle,
                    (fs_index_t)uint16_t_le2host(d->firstc),
                    parentp->index);
                block_put(b);
                return node;
            }
        }
        block_put(b);
    }
 
    return NULL;
}
 
static fs_index_t fat_index_get(void *node)
{
    fat_node_t *fnodep = (fat_node_t *)node;
    if (!fnodep)
        return 0;
    return fnodep->index;
}
 
static size_t fat_size_get(void *node)
{
    return ((fat_node_t *)node)->size;
}
 
static unsigned fat_lnkcnt_get(void *node)
{
    return ((fat_node_t *)node)->lnkcnt;
}
 
static bool fat_has_children(void *node)
{
    fat_node_t *nodep = (fat_node_t *)node;
    unsigned bps;
    unsigned dps;
    unsigned blocks;
    block_t *b;
    unsigned i, j;
 
    if (nodep->type != FAT_DIRECTORY)
        return false;
 
    bps = fat_bps_get(nodep->dev_handle);
    dps = bps / sizeof(fat_dentry_t);
 
    blocks = nodep->size / bps + (nodep->size % bps != 0);
 
    for (i = 0; i < blocks; i++) {
        unsigned dentries;
        fat_dentry_t *d;
   
        b = fat_block_get(nodep->dev_handle, nodep->index, i);
        dentries = (i == blocks - 1) ?
            nodep->size % sizeof(fat_dentry_t) :
            dps;
        for (j = 0; j < dentries; j++) {
            d = ((fat_dentry_t *)b->data) + j;
            switch (fat_classify_dentry(d)) {
            case FAT_DENTRY_SKIP:
                continue;
            case FAT_DENTRY_LAST:
                block_put(b);
                return false;
            default:
            case FAT_DENTRY_VALID:
                block_put(b);
                return true;
            }
            block_put(b);
            return true;
        }
        block_put(b);
    }
 
    return false;
}
 
static void *fat_root_get(dev_handle_t dev_handle)
{
    return fat_node_get(dev_handle, 0, 0); 
}
 
static char fat_plb_get_char(unsigned pos)
{
    return fat_reg.plb_ro[pos % PLB_SIZE];
}
 
static bool fat_is_directory(void *node)
{
    return ((fat_node_t *)node)->type == FAT_DIRECTORY;
}
 
static bool fat_is_file(void *node)
{
    return ((fat_node_t *)node)->type == FAT_FILE;
}
 
/** libfs operations */
libfs_ops_t fat_libfs_ops = {
    .match = fat_match,
    .node_get = fat_node_get,
    .node_put = fat_node_put,
    .create = NULL,
    .destroy = NULL,
    .link = NULL,
    .unlink = NULL,
    .index_get = fat_index_get,
    .size_get = fat_size_get,
    .lnkcnt_get = fat_lnkcnt_get,
    .has_children = fat_has_children,
    .root_get = fat_root_get,
    .plb_get_char = fat_plb_get_char,
    .is_directory = fat_is_directory,
    .is_file = fat_is_file
};
 
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
{
    libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
}
 
/**
 * @}
 */
 

Rev 2852	Rev 2855
1	/*	1	/*
2	* Copyright (c) 2008 Jakub Jermar	2	* Copyright (c) 2008 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup fs	29	/** @addtogroup fs
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file fat_ops.c	34	* @file fat_ops.c
35	* @brief Implementation of VFS operations for the FAT file system server.	35	* @brief Implementation of VFS operations for the FAT file system server.
36	*/	36	*/
37		37
38	#include "fat.h"	38	#include "fat.h"
39	#include "../../vfs/vfs.h"	39	#include "../../vfs/vfs.h"
40	#include <libfs.h>	40	#include <libfs.h>
41	#include <ipc/ipc.h>	41	#include <ipc/ipc.h>
42	#include <async.h>	42	#include <async.h>
43	#include <errno.h>	43	#include <errno.h>
44	#include <string.h>	44	#include <string.h>
45	#include <byteorder.h>	45	#include <byteorder.h>
46	#include <libadt/hash_table.h>	46	#include <libadt/hash_table.h>
47	#include <libadt/list.h>	47	#include <libadt/list.h>
48	#include <assert.h>	48	#include <assert.h>
49		49
50	#define BS_BLOCK 0	50	#define BS_BLOCK 0
51		51
52	#define FIN_KEY_DEV_HANDLE 0	52	#define FIN_KEY_DEV_HANDLE 0
53	#define FIN_KEY_INDEX 1	53	#define FIN_KEY_INDEX 1
54		54
55	/** Hash table of FAT in-core nodes. */	55	/** Hash table of FAT in-core nodes. */
56	hash_table_t fin_hash;	56	hash_table_t fin_hash;
57		57
58	/** List of free FAT in-core nodes. */	58	/** List of free FAT in-core nodes. */
59	link_t ffn_head;	59	link_t ffn_head;
60		60
61	#define FAT_NAME_LEN 8	61	#define FAT_NAME_LEN 8
62	#define FAT_EXT_LEN 3	62	#define FAT_EXT_LEN 3
63		63
64	#define FAT_PAD ' '	64	#define FAT_PAD ' '
65		65
66	#define FAT_DENTRY_UNUSED 0x00	66	#define FAT_DENTRY_UNUSED 0x00
67	#define FAT_DENTRY_E5_ESC 0x05	67	#define FAT_DENTRY_E5_ESC 0x05
68	#define FAT_DENTRY_DOT 0x2e	68	#define FAT_DENTRY_DOT 0x2e
69	#define FAT_DENTRY_ERASED 0xe5	69	#define FAT_DENTRY_ERASED 0xe5
70		70
71	static void dentry_name_canonify(fat_dentry_t d, char buf)	71	static void dentry_name_canonify(fat_dentry_t d, char buf)
72	{	72	{
73	int i;	73	int i;
74		74
75	for (i = 0; i < FAT_NAME_LEN; i++) {	75	for (i = 0; i < FAT_NAME_LEN; i++) {
76	if (d->name[i] == FAT_PAD) {	76	if (d->name[i] == FAT_PAD) {
77	buf++;	77	buf++;
78	break;	78	break;
79	}	79	}
80	if (d->name[i] == FAT_DENTRY_E5_ESC)	80	if (d->name[i] == FAT_DENTRY_E5_ESC)
81	*buf++ = 0xe5;	81	*buf++ = 0xe5;
82	else	82	else
83	*buf++ = d->name[i];	83	*buf++ = d->name[i];
84	}	84	}
85	if (d->ext[0] != FAT_PAD)	85	if (d->ext[0] != FAT_PAD)
86	*buf++ = '.';	86	*buf++ = '.';
87	for (i = 0; i < FAT_EXT_LEN; i++) {	87	for (i = 0; i < FAT_EXT_LEN; i++) {
88	if (d->ext[i] == FAT_PAD) {	88	if (d->ext[i] == FAT_PAD) {
89	*buf = '\0';	89	*buf = '\0';
90	return;	90	return;
91	}	91	}
92	if (d->ext[i] == FAT_DENTRY_E5_ESC)	92	if (d->ext[i] == FAT_DENTRY_E5_ESC)
93	*buf++ = 0xe5;	93	*buf++ = 0xe5;
94	else	94	else
95	*buf++ = d->ext[i];	95	*buf++ = d->ext[i];
96	}	96	}
97	}	97	}
98		98
99	/* TODO and also move somewhere else */	99	/* TODO and also move somewhere else */
100	typedef struct {	100	typedef struct {
101	void *data;	101	void *data;
102	} block_t;	102	} block_t;
103		103
104	static block_t *block_get(dev_handle_t dev_handle, off_t offset)	104	static block_t *block_get(dev_handle_t dev_handle, off_t offset)
105	{	105	{
106	return NULL; /* TODO */	106	return NULL; /* TODO */
107	}	107	}
108		108
109	static block_t *fat_block_get(dev_handle_t dev_handle, fs_index_t index,	109	static block_t *fat_block_get(dev_handle_t dev_handle, fs_index_t index,
110	off_t offset) {	110	off_t offset) {
111	return NULL; /* TODO */	111	return NULL; /* TODO */
112	}	112	}
113		113
114	static void block_put(block_t *block)	114	static void block_put(block_t *block)
115	{	115	{
116	/* TODO */	116	/* TODO */
117	}	117	}
118		118
119	static void fat_node_initialize(fat_node_t *node)	119	static void fat_node_initialize(fat_node_t *node)
120	{	120	{
121	node->type = 0;	121	node->type = 0;
122	node->index = 0;	122	node->index = 0;
123	node->pindex = 0;	123	node->pindex = 0;
124	node->dev_handle = 0;	124	node->dev_handle = 0;
125	link_initialize(&node->fin_link);	125	link_initialize(&node->fin_link);
126	link_initialize(&node->ffn_link);	126	link_initialize(&node->ffn_link);
127	node->size = 0;	127	node->size = 0;
128	node->lnkcnt = 0;	128	node->lnkcnt = 0;
129	node->refcnt = 0;	129	node->refcnt = 0;
130	node->dirty = false;	130	node->dirty = false;
131	}	131	}
132		132
133	static uint16_t fat_bps_get(dev_handle_t dev_handle)	133	static uint16_t fat_bps_get(dev_handle_t dev_handle)
134	{	134	{
135	block_t *bb;	135	block_t *bb;
136	uint16_t bps;	136	uint16_t bps;
137		137
138	bb = block_get(dev_handle, BS_BLOCK);	138	bb = block_get(dev_handle, BS_BLOCK);
139	assert(bb != NULL);	139	assert(bb != NULL);
140	bps = uint16_t_le2host(((fat_bs_t *)bb->data)->bps);	140	bps = uint16_t_le2host(((fat_bs_t *)bb->data)->bps);
141	block_put(bb);	141	block_put(bb);
142		142
143	return bps;	143	return bps;
144	}	144	}
145		145
146	typedef enum {	146	typedef enum {
147	FAT_DENTRY_SKIP,	147	FAT_DENTRY_SKIP,
148	FAT_DENTRY_LAST,	148	FAT_DENTRY_LAST,
149	FAT_DENTRY_VALID	149	FAT_DENTRY_VALID
150	} fat_dentry_clsf_t;	150	} fat_dentry_clsf_t;
151		151
152	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)	152	static fat_dentry_clsf_t fat_classify_dentry(fat_dentry_t *d)
153	{	153	{
154	if (d->attr & FAT_ATTR_VOLLABEL) {	154	if (d->attr & FAT_ATTR_VOLLABEL) {
155	/* volume label entry */	155	/* volume label entry */
156	return FAT_DENTRY_SKIP;	156	return FAT_DENTRY_SKIP;
157	}	157	}
158	if (d->name[0] == FAT_DENTRY_ERASED) {	158	if (d->name[0] == FAT_DENTRY_ERASED) {
159	/* not-currently-used entry */	159	/* not-currently-used entry */
160	return FAT_DENTRY_SKIP;	160	return FAT_DENTRY_SKIP;
161	}	161	}
162	if (d->name[0] == FAT_DENTRY_UNUSED) {	162	if (d->name[0] == FAT_DENTRY_UNUSED) {
163	/* never used entry */	163	/* never used entry */
164	return FAT_DENTRY_LAST;	164	return FAT_DENTRY_LAST;
165	}	165	}
166	if (d->name[0] == FAT_DENTRY_DOT) {	166	if (d->name[0] == FAT_DENTRY_DOT) {
167	/*	167	/*
168	* Most likely '.' or '..'.	168	* Most likely '.' or '..'.
169	* It cannot occur in a regular file name.	169	* It cannot occur in a regular file name.
170	*/	170	*/
171	return FAT_DENTRY_SKIP;	171	return FAT_DENTRY_SKIP;
172	}	172	}
173	return FAT_DENTRY_VALID;	173	return FAT_DENTRY_VALID;
174	}	174	}
175		175
176	static void fat_sync_node(fat_node_t *node)	176	static void fat_sync_node(fat_node_t *node)
177	{	177	{
178	/* TODO */	178	/* TODO */
179	}	179	}
180		180
181	/** Instantiate a FAT in-core node.	181	/** Instantiate a FAT in-core node.
182	*	182	*
183	* FAT stores the info necessary for instantiation of a node in the parent of	183	* FAT stores the info necessary for instantiation of a node in the parent of
184	* that node. This design necessitated the addition of the parent node index	184	* that node. This design necessitated the addition of the parent node index
185	* parameter to this otherwise generic libfs API.	185	* parameter to this otherwise generic libfs API.
186	*/	186	*/
187	static void *	187	static void *
188	fat_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)	188	fat_node_get(dev_handle_t dev_handle, fs_index_t index, fs_index_t pindex)
189	{	189	{
190	link_t *lnk;	190	link_t *lnk;
191	fat_node_t *node = NULL;	191	fat_node_t *node = NULL;
192	block_t *b;	192	block_t *b;
193	unsigned bps;	193	unsigned bps;
194	unsigned dps;	194	unsigned dps;
195	fat_dentry_t *d;	195	fat_dentry_t *d;
196	unsigned i, j;	196	unsigned i, j;
197		197
198	unsigned long key[] = {	198	unsigned long key[] = {
199	[FIN_KEY_DEV_HANDLE] = dev_handle,	199	[FIN_KEY_DEV_HANDLE] = dev_handle,
200	[FIN_KEY_INDEX] = index	200	[FIN_KEY_INDEX] = index
201	};	201	};
202		202
203	lnk = hash_table_find(&fin_hash, key);	203	lnk = hash_table_find(&fin_hash, key);
204	if (lnk) {	204	if (lnk) {
205	/*	205	/*
206	* The in-core node was found in the hash table.	206	* The in-core node was found in the hash table.
207	*/	207	*/
208	node = hash_table_get_instance(lnk, fat_node_t, fin_link);	208	node = hash_table_get_instance(lnk, fat_node_t, fin_link);
209	if (!node->refcnt++)	209	if (!node->refcnt++)
210	list_remove(&node->ffn_link);	210	list_remove(&node->ffn_link);
211	return (void *) node;	211	return (void *) node;
212	}	212	}
213		213
214	bps = fat_bps_get(dev_handle);	214	bps = fat_bps_get(dev_handle);
215	dps = bps / sizeof(fat_dentry_t);	215	dps = bps / sizeof(fat_dentry_t);
216		216
217	if (!list_empty(&ffn_head)) {	217	if (!list_empty(&ffn_head)) {
218	/*	218	/*
219	* We are going to reuse a node from the free list.	219	* We are going to reuse a node from the free list.
220	*/	220	*/
221	lnk = ffn_head.next;	221	lnk = ffn_head.next;
222	list_remove(lnk);	222	list_remove(lnk);
223	node = list_get_instance(lnk, fat_node_t, ffn_link);	223	node = list_get_instance(lnk, fat_node_t, ffn_link);
224	assert(!node->refcnt);	224	assert(!node->refcnt);
225	if (node->dirty)	225	if (node->dirty)
226	fat_sync_node(node);	226	fat_sync_node(node);
227	key[FIN_KEY_DEV_HANDLE] = node->dev_handle;	227	key[FIN_KEY_DEV_HANDLE] = node->dev_handle;
228	key[FIN_KEY_INDEX] = node->index;	228	key[FIN_KEY_INDEX] = node->index;
229	hash_table_remove(&fin_hash, key, sizeof(key)/sizeof(*key));	229	hash_table_remove(&fin_hash, key, sizeof(key)/sizeof(*key));
230	} else {	230	} else {
231	/*	231	/*
232	* We need to allocate a new node.	232	* We need to allocate a new node.
233	*/	233	*/
234	node = malloc(sizeof(fat_node_t));	234	node = malloc(sizeof(fat_node_t));
235	if (!node)	235	if (!node)
236	return NULL;	236	return NULL;
237	}	237	}
238	fat_node_initialize(node);	238	fat_node_initialize(node);
239	node->refcnt++;	239	node->refcnt++;
240	node->lnkcnt++;	240	node->lnkcnt++;
241	node->dev_handle = dev_handle;	241	node->dev_handle = dev_handle;
242	node->index = index;	242	node->index = index;
243	node->pindex = pindex;	243	node->pindex = pindex;
244		244
245	/*	245	/*
246	* Because of the design of the FAT file system, we have no clue about	246	* Because of the design of the FAT file system, we have no clue about
247	* how big (i.e. how many directory entries it contains) is the parent	247	* how big (i.e. how many directory entries it contains) is the parent
248	* of the node we are trying to instantiate. However, we know that it	248	* of the node we are trying to instantiate. However, we know that it
249	* must contain a directory entry for our node of interest. We simply	249	* must contain a directory entry for our node of interest. We simply
250	* scan the parent until we find it.	250	* scan the parent until we find it.
251	*/	251	*/
252	for (i = 0; ; i++) {	252	for (i = 0; ; i++) {
253	b = fat_block_get(node->dev_handle, node->pindex, i);	253	b = fat_block_get(node->dev_handle, node->pindex, i);
254	for (j = 0; j < dps; j++) {	254	for (j = 0; j < dps; j++) {
255	d = ((fat_dentry_t *)b->data) + j;	255	d = ((fat_dentry_t *)b->data) + j;
256	if (d->firstc == node->index)	256	if (d->firstc == node->index)
257	goto found;	257	goto found;
258	}	258	}
259	block_put(b);	259	block_put(b);
260	}	260	}
261		261
262	found:	262	found:
263	if (!(d->attr & (FAT_ATTR_SUBDIR \| FAT_ATTR_VOLLABEL)))	263	if (!(d->attr & (FAT_ATTR_SUBDIR \| FAT_ATTR_VOLLABEL)))
264	node->type = FAT_FILE;	264	node->type = FAT_FILE;
265	if ((d->attr & FAT_ATTR_SUBDIR) \|\| !index)	265	if ((d->attr & FAT_ATTR_SUBDIR) \|\| !index)
266	node->type = FAT_DIRECTORY;	266	node->type = FAT_DIRECTORY;
267	assert((node->type == FAT_FILE) \|\| (node->type == FAT_DIRECTORY));	267	assert((node->type == FAT_FILE) \|\| (node->type == FAT_DIRECTORY));
268		268
269	node->size = uint32_t_le2host(d->size);	269	node->size = uint32_t_le2host(d->size);
270	block_put(b);	270	block_put(b);
271		271
272	key[FIN_KEY_DEV_HANDLE] = node->dev_handle;	272	key[FIN_KEY_DEV_HANDLE] = node->dev_handle;
273	key[FIN_KEY_INDEX] = node->index;	273	key[FIN_KEY_INDEX] = node->index;
274	hash_table_insert(&fin_hash, key, &node->fin_link);	274	hash_table_insert(&fin_hash, key, &node->fin_link);
275		275
276	return node;	276	return node;
277	}	277	}
278		278
279	static void fat_node_put(void *node)	279	static void fat_node_put(void *node)
280	{	280	{
-		281	fat_node_t nodep = (fat_node_t )node;
-		282
281	/* TODO */	283	if (nodep->refcnt-- == 1)
-		284	list_append(&nodep->ffn_link, &ffn_head);
282	}	285	}
283		286
284	static void fat_match(void prnt, const char *component)	287	static void fat_match(void prnt, const char *component)
285	{	288	{
286	fat_node_t parentp = (fat_node_t )prnt;	289	fat_node_t parentp = (fat_node_t )prnt;
287	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];	290	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
288	unsigned i, j;	291	unsigned i, j;
289	unsigned bps; /* bytes per sector */	292	unsigned bps; /* bytes per sector */
290	unsigned dps; /* dentries per sector */	293	unsigned dps; /* dentries per sector */
291	unsigned blocks;	294	unsigned blocks;
292	fat_dentry_t *d;	295	fat_dentry_t *d;
293	block_t *b;	296	block_t *b;
294		297
295	bps = fat_bps_get(parentp->dev_handle);	298	bps = fat_bps_get(parentp->dev_handle);
296	dps = bps / sizeof(fat_dentry_t);	299	dps = bps / sizeof(fat_dentry_t);
297	blocks = parentp->size / bps + (parentp->size % bps != 0);	300	blocks = parentp->size / bps + (parentp->size % bps != 0);
298	for (i = 0; i < blocks; i++) {	301	for (i = 0; i < blocks; i++) {
299	unsigned dentries;	302	unsigned dentries;
300		303
301	b = fat_block_get(parentp->dev_handle, parentp->index, i);	304	b = fat_block_get(parentp->dev_handle, parentp->index, i);
302	dentries = (i == blocks - 1) ?	305	dentries = (i == blocks - 1) ?
303	parentp->size % sizeof(fat_dentry_t) :	306	parentp->size % sizeof(fat_dentry_t) :
304	dps;	307	dps;
305	for (j = 0; j < dentries; j++) {	308	for (j = 0; j < dentries; j++) {
306	d = ((fat_dentry_t *)b->data) + j;	309	d = ((fat_dentry_t *)b->data) + j;
307	switch (fat_classify_dentry(d)) {	310	switch (fat_classify_dentry(d)) {
308	case FAT_DENTRY_SKIP:	311	case FAT_DENTRY_SKIP:
309	continue;	312	continue;
310	case FAT_DENTRY_LAST:	313	case FAT_DENTRY_LAST:
311	block_put(b);	314	block_put(b);
312	return NULL;	315	return NULL;
313	default:	316	default:
314	case FAT_DENTRY_VALID:	317	case FAT_DENTRY_VALID:
315	dentry_name_canonify(d, name);	318	dentry_name_canonify(d, name);
316	break;	319	break;
317	}	320	}
318	if (strcmp(name, component) == 0) {	321	if (strcmp(name, component) == 0) {
319	/* hit */	322	/* hit */
320	void *node = fat_node_get(parentp->dev_handle,	323	void *node = fat_node_get(parentp->dev_handle,
321	(fs_index_t)uint16_t_le2host(d->firstc),	324	(fs_index_t)uint16_t_le2host(d->firstc),
322	parentp->index);	325	parentp->index);
323	block_put(b);	326	block_put(b);
324	return node;	327	return node;
325	}	328	}
326	}	329	}
327	block_put(b);	330	block_put(b);
328	}	331	}
329		332
330	return NULL;	333	return NULL;
331	}	334	}
332		335
333	static fs_index_t fat_index_get(void *node)	336	static fs_index_t fat_index_get(void *node)
334	{	337	{
335	fat_node_t fnodep = (fat_node_t )node;	338	fat_node_t fnodep = (fat_node_t )node;
336	if (!fnodep)	339	if (!fnodep)
337	return 0;	340	return 0;
338	return fnodep->index;	341	return fnodep->index;
339	}	342	}
340		343
341	static size_t fat_size_get(void *node)	344	static size_t fat_size_get(void *node)
342	{	345	{
343	return ((fat_node_t *)node)->size;	346	return ((fat_node_t *)node)->size;
344	}	347	}
345		348
346	static unsigned fat_lnkcnt_get(void *node)	349	static unsigned fat_lnkcnt_get(void *node)
347	{	350	{
348	return ((fat_node_t *)node)->lnkcnt;	351	return ((fat_node_t *)node)->lnkcnt;
349	}	352	}
350		353
351	static bool fat_has_children(void *node)	354	static bool fat_has_children(void *node)
352	{	355	{
353	fat_node_t nodep = (fat_node_t )node;	356	fat_node_t nodep = (fat_node_t )node;
354	unsigned bps;	357	unsigned bps;
355	unsigned dps;	358	unsigned dps;
356	unsigned blocks;	359	unsigned blocks;
357	block_t *b;	360	block_t *b;
358	unsigned i, j;	361	unsigned i, j;
359		362
360	if (nodep->type != FAT_DIRECTORY)	363	if (nodep->type != FAT_DIRECTORY)
361	return false;	364	return false;
362		365
363	bps = fat_bps_get(nodep->dev_handle);	366	bps = fat_bps_get(nodep->dev_handle);
364	dps = bps / sizeof(fat_dentry_t);	367	dps = bps / sizeof(fat_dentry_t);
365		368
366	blocks = nodep->size / bps + (nodep->size % bps != 0);	369	blocks = nodep->size / bps + (nodep->size % bps != 0);
367		370
368	for (i = 0; i < blocks; i++) {	371	for (i = 0; i < blocks; i++) {
369	unsigned dentries;	372	unsigned dentries;
370	fat_dentry_t *d;	373	fat_dentry_t *d;
371		374
372	b = fat_block_get(nodep->dev_handle, nodep->index, i);	375	b = fat_block_get(nodep->dev_handle, nodep->index, i);
373	dentries = (i == blocks - 1) ?	376	dentries = (i == blocks - 1) ?
374	nodep->size % sizeof(fat_dentry_t) :	377	nodep->size % sizeof(fat_dentry_t) :
375	dps;	378	dps;
376	for (j = 0; j < dentries; j++) {	379	for (j = 0; j < dentries; j++) {
377	d = ((fat_dentry_t *)b->data) + j;	380	d = ((fat_dentry_t *)b->data) + j;
378	switch (fat_classify_dentry(d)) {	381	switch (fat_classify_dentry(d)) {
379	case FAT_DENTRY_SKIP:	382	case FAT_DENTRY_SKIP:
380	continue;	383	continue;
381	case FAT_DENTRY_LAST:	384	case FAT_DENTRY_LAST:
382	block_put(b);	385	block_put(b);
383	return false;	386	return false;
384	default:	387	default:
385	case FAT_DENTRY_VALID:	388	case FAT_DENTRY_VALID:
386	block_put(b);	389	block_put(b);
387	return true;	390	return true;
388	}	391	}
389	block_put(b);	392	block_put(b);
390	return true;	393	return true;
391	}	394	}
392	block_put(b);	395	block_put(b);
393	}	396	}
394		397
395	return false;	398	return false;
396	}	399	}
397		400
398	static void *fat_root_get(dev_handle_t dev_handle)	401	static void *fat_root_get(dev_handle_t dev_handle)
399	{	402	{
400	return fat_node_get(dev_handle, 0, 0);	403	return fat_node_get(dev_handle, 0, 0);
401	}	404	}
402		405
403	static char fat_plb_get_char(unsigned pos)	406	static char fat_plb_get_char(unsigned pos)
404	{	407	{
405	return fat_reg.plb_ro[pos % PLB_SIZE];	408	return fat_reg.plb_ro[pos % PLB_SIZE];
406	}	409	}
407		410
408	static bool fat_is_directory(void *node)	411	static bool fat_is_directory(void *node)
409	{	412	{
410	return ((fat_node_t *)node)->type == FAT_DIRECTORY;	413	return ((fat_node_t *)node)->type == FAT_DIRECTORY;
411	}	414	}
412		415
413	static bool fat_is_file(void *node)	416	static bool fat_is_file(void *node)
414	{	417	{
415	return ((fat_node_t *)node)->type == FAT_FILE;	418	return ((fat_node_t *)node)->type == FAT_FILE;
416	}	419	}
417		420
418	/** libfs operations */	421	/** libfs operations */
419	libfs_ops_t fat_libfs_ops = {	422	libfs_ops_t fat_libfs_ops = {
420	.match = fat_match,	423	.match = fat_match,
421	.node_get = fat_node_get,	424	.node_get = fat_node_get,
422	.node_put = fat_node_put,	425	.node_put = fat_node_put,
423	.create = NULL,	426	.create = NULL,
424	.destroy = NULL,	427	.destroy = NULL,
425	.link = NULL,	428	.link = NULL,
426	.unlink = NULL,	429	.unlink = NULL,
427	.index_get = fat_index_get,	430	.index_get = fat_index_get,
428	.size_get = fat_size_get,	431	.size_get = fat_size_get,
429	.lnkcnt_get = fat_lnkcnt_get,	432	.lnkcnt_get = fat_lnkcnt_get,
430	.has_children = fat_has_children,	433	.has_children = fat_has_children,
431	.root_get = fat_root_get,	434	.root_get = fat_root_get,
432	.plb_get_char = fat_plb_get_char,	435	.plb_get_char = fat_plb_get_char,
433	.is_directory = fat_is_directory,	436	.is_directory = fat_is_directory,
434	.is_file = fat_is_file	437	.is_file = fat_is_file
435	};	438	};
436		439
437	void fat_lookup(ipc_callid_t rid, ipc_call_t *request)	440	void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
438	{	441	{
439	libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);	442	libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
440	}	443	}
441		444
442	/**	445	/**
443	* @}	446	* @}
444	*/	447	*/
445		448

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c – Rev 2852 → 2855